Data‐fused digital bathymetry and side‐scan sonar as a base for archaeological inventory of submerged landscapes in the Rideau Canal, Ontario, Canada

Abstract Colonel By Lake, located near Kingston, Ontario, was created in the early 19th century during the construction of the Rideau Canal waterway. Canal flooding inundated a large area of the Cataraqui River lowlands, submerging important pre‐contact and colonial settlements. In order to gain a better understanding of the pre‐canal environment and its archaeological setting, a systematic bathymetry and side‐scan sonar survey was conducted over a 2‐km2 area of Colonel By Lake. A 2‐D digital bathymetric model (DBM) of the lake bottom was constructed and overlain with side‐scan mosaics to map the paleogeography of the river flood plain. The data‐fused sonar images clearly identify the submerged pre‐canal topography, including the former Cataraqui River channel, relict meanders, tree stump fields, and bedrock uplands defining the valley sides. By comparing the DBM with landscapes depicted in pre‐canal period maps (ca. 1828), the locations of several potential archaeological targets were identified. The DBM provides a basis for mapping submerged cultural resources in the Rideau and for predicting the location of undiscovered archaeological sites. The results show that integration of single‐beam bathymetric mapping with side‐scan imagery is an effective strategy for mapping submerged terrestrial landscapes and archaeological inventory in shallow water settings. © 2008 Wiley Periodicals, Inc.